Girder and the like for aircraft



E. E. BROWN.

GIRDER AND THE LIKE FOR AIRCRAFT.

Patented Aug. 31, 1920 A WORD/E78 UNETED STATES EDWARD EUGENE BROWN, OF STREATHAM, LONDON, ENGLAND;

GIBDER AND THE LIKE FOR AIRCRAFT.

Specification of Letters Patent.

Patented Aug. 31, teen.

Application filed January 26, 1918. Serial No. 213;980.

To all whom it may concern:

Be it known that I, EDWARD EUGENE BROWN, a subject of the King of England, and a resident of Streatham, London, S. lV., England, have invented new and useful Improvements in or Relating to Girdel's and the like for Aircraft, of which the following is a full, clear, and exact description.

The invention is for improvements in or relating to girders and the like for aircraft and has for its object to provide a metal girder or equivalent structurefor aircraft which shall be stiffer and stronger in proportion to its weight than has heretofore been obtainable.

According to this invention, the girder comprises composite channel members placed back to back, characterized by the web portion being provided with parallel ribs which are set obliquely to thelongitudinal direction of the girder, the ribs of one channel member moreover being sloped in the opposite direction to those of the other so that they present a triangulated form which increases the parallel resistance of the girder to deflect-ion or fracture.

The ribs are preferably so spaced apart that sufficient width is allowed between them for riveting.

Additional objects of the invention will appear in the following specification in which the preferred form of my invention is described.

In the drawings, similar reference characters refer to similar parts in all the views, in which Figure l is a perspective sectional view of the end portion of a girder constructed according to one method of carrying out this invention.

Fig. 2 is an elevation of a portion of the paneling showing the cross arrangement of the ribs on the back panel.

Figs. 3 and 4 are elevations of panels 1 showing other forms of ribbing.

Fig. 5 is an elevation of a portion of paneling showing a possible arrangement of ribbing at the center of the panel.

Fig. 6 is a perspective sectional view of another construction of girder according to this invention, and

Fig. 7 is a sectional elevation of a panel in which the form of rib shown in Fig. 6 is modified.

The composite girder shown in Fig. 1

comprises two upper U shaped members A, A placed side by side, the meeting flanges A of these members being longer than the outer flanges A thereof. Corresponding bottom shaped members A, A are provided and placed with their meeting flanges together, which flanges again are longer than the outer flanges.

The composite girder is completed by panels B, B which constitute webs for the U-shaped members which panels are riveted together and to themiddle flanges A of the U shaped members by rivets indicated at C. If desired, the ribs may be riveted to the outer flanges A as indicated at A. The panels B, B are provided with parallel ribs which are set obliquely to the longitudinal direction of the girder, and the ribs on the panel B slope inthe reverse direction to those on the panel B In Fig. 2, which is a face view of the panel B, the opposite slope of the ribs on the panel B is indicated in dotted lines. It will be seen that this construction of girder, while affording lightness also affords great rigidity. The ribs lie within the U shaped members and their crests preferably bear against the outer flanges of the same while their bases are secured to the inner flanges A by rivets as aforesaid, or the bases may be secured to the outer flanges, and the crest against the inner flanges, and the crossing of the ribs of one panel relatively to the other braces the girder against stresses in all directions. It will be seen that this crossing is such that each front rib constitutes two sides-of a triangle with a corresponding back rib.

An important feature of the ribbing is the provision of a wide foot B between the ribs. This arrangement makes room for sethe riveting can be effected without undue labor with consequent loss of time.

Instead of the ribs extending across the whole width of the panel, alternate ribs may be carried part way only, as shown at D in Fig. 3. The panels and U-shaped members may be riveted together as indicated at D though the U shaped members are not shown in this figure.

In Fig. 4, ribs E and E are shown which start alternately fromopposite sides of the panel and do not extend right across the same.

Whatever form of rib is employed, their slope may be reversed at the center of the panel, as indicated in Fig. 5. When two panels are used with reversal of the slope of the ribs at the center, one may be inverted relatively to the other as indicated by the drawings) placed between the top and bottom members F. The panel G is provided with'ribs G which extend part way across the anel in a manner similar to ribs E, E of ig. 4, but the top and bottom ed es of the panel are bent outwardly at G 3 respectively of the top and bottom members F; The

edges of the parts G G butt against turned-over edges on the said outer flanges and thus serve to stiffen these, and the panels are secured to the web oi? the inner flanges by rivets placed in the spaces H, which spaces afford room for driving them home; the same rivets may secure the two panels in place and the two U shaped members together.

Each rib G is continued at one end into flat portion (ii of the panel to stiffen these parts.

In Fig. 7 another form of panel is shown in which the ribs J do not extend either to the top or bottom of the panel and they are crossed by a middle rib J A panel constructed with ribs J, J may be applied to the construction shown in Fig. 1 or the construction shown in Fig. .6; in the latter case, the top and bottom edges would be bent out, as shown with the edges G G to support the flanges of the. U shaped members with whichthe panelis to be used.

It will be appreciated that any one of the arrangements of ribs shown on the different panels may be applied to a composite girder having separate U shaped members top and bottom as in Fig. 1, but if the panel is to be provided with a foot top and bottom to support the flanges, for this purpose beyond the ribbing.

Although riveting has been referred to throughout this specification as the means of fastening, spot-welding or other known means may be employed in lieu of riveting.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

'1. In a girder, a pair of members having inner flanges disposed side'by side and outer flanges, a second pair of members having inner flanges disposed side by side and outer flanges, the second mentioned members being spaced from the first mentioned members, two panels, each provided with ribs, and having their sides disposed at the inner flanges, means to secure the sides of the panto strengthen the outer flanges F a flat portion must be left portions of the flanges;

3. In a girder, two panels disposed back to back, each provided with ribs, members having outwardly and downwardly extending flanges at the edges of the panels, means to secure the panels to the members, and means to secure the ribs on the panels to the outer portions of the flanges.

4. In a girder, two members disposed back to back and each having transverse ribs joined byan integral longitudinally disposed rib.

5. In a girder, a member having a plurality of transverse ribs joinedby an integral longitudinally disposed rib.

6. In a girder, a pair of members having flanges disposed side by side, a second pair of members having flanges disposed side by side, the second mentioned members being spaced from the first mentioned members, and two panels each provided with ribs and having their ends disposed at the flanges, and means to secure the sides of the panels and the flanges together.

7. In a girder, a member having a plurality of transverse ribs joined between their ends with an integral longitudinally disposed rib.

8. In a girder, a member having a plurality of staggered parallel transverseribs.

9. In a girder, two panels disposed back to back, each provided with obliquely disposed ribs, the 'slope of the ribs on a portion of each panel being reversed relative to the slope of the ribs on another portion of the panel, members having outwardly-'extend ing flanges at the edges of the panels, means to secure the panels between their ribs to the members, and means to secure the ribs to the outer portions of the flanges.

10. In a girder, two panels disposed back .to back, each provided with ribs which extend to their edges, members having outwardly and downwardly extending portions at the edges of the panels and ends of the ribs, the inner sides of which are secured to the panels the outer sides being secured to the ribs.

11. In a girder, two panels disposed back to back, each provided with ribs, members disposed at the edges of the panels and having outer flanges with their edges bent downwardly substantially parallel with the bodies of the panels, means to secure the panels to the members, and means to secure the said edges of the flanges to the ribs.

EDWVARD EUGENE BROWN.

Ill 

